California Academy of Sciences 55 Music Concourse Dr., in Golden Gate Park. Fee. This oldest scientific institution in the West was founded in 1853 following the Gold Rush. Newly rebuilt, it combines an aquarium, planetarium, natural history museum, and scientific research facilities under one roof. Visitors can explore the outer reaches of the galaxy in the world’s largest all-digital planetarium, get a bird’s-eye view of a Costa Rican rainforest canopy, and view the world’s deepest display of living corals. The new building is topped with a 2.5-acre living roof and employs a wide range of energy-saving materials and technologies. More than 38,000 live animals fill the aquarium and natural history exhibits--one of the most diverse collections of live animals at any museum or aquarium in the world. Allow four hours, and aim for Tuesday, Wednesday, or Thursday for less crowding. Must-sees include the living roof, 4-story rainforest, Philippine coral reef, earthquake simulation, African penguins, and albino alligator. Casual Academy Cafe has a menu of sandwiches, tacos, pastries, and more.

Exploratorium Pier 15, The Embarcadero. Fee. Now moved from the Palace of Fine Arts into its new $300 million reconstructed pier home over the bay, this famous museum has three times more space to present a combination of play and learning that is as much fun for adults as it is for kids. It adds up to more than 150 new interactive exhibits among the total of more than 600. I love that there are free exhibits outside the entrance, allowing you to get a taste for what is inside, because entry is an investment. I was seduced outside by the rickety Rickshaw Obscura, which really reeled as I climbed in. I have found only two other camera obscuras in California and do have an interest in “collecting” experiences with these old-time pinhole cameras that allow you to sit in the dark and view what is going on outside. I was reeled in by teenage “Explainer” Rhonda Gaynor (they are found throughout, wearing easy-to-see orange vests and wandering the premises ready to assist). Inside, the gigantic pier setting is broken into smaller sections and is abuzz with excitement. I thought the Sweepers Clock was very clever and fun to watch:

and I stuck around to watch a giant Mexican pendulum clock strike noon, but was hugely disappointed by just a few weak dongs:

when I was expecting this:

I recommend walking down the museum’s center, then returning via the corridor down the south side. A dissection demonstration is usually occuring at the bay end—perhaps a cow’s eye or, if you’re lucky, a flower—and don’t miss the upstairs gallery at that end for a dead-on view of Treasure Island and the bay, not to mention another small camera obscura. I appreciated the rocking chair gallery found at the beginning of my trek back. The Tactile Dome is a geodesic dome with 13 chambers through which visitors walk, crawl, slide, climb, and tumble in complete darkness using only their sense of touch to guide them. Participants must be age 7 or older, and reservations are required. The dome was designed and built in 1971 by August Coppola (father of actor Nicolas Cage and brother of film director Francis Ford Coppola).Seaglass restaurant consists of four cafeteria stations serving up sushi, pizza, tacos, and sandwiches plus wine, beer, and cocktails.